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Denial-of-service attacks (DoS) – Types And Preventions A Complete Guide

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Denial-of-service attacks (DoS) - Types And Preventions A Complete Guide

Denial-of-service attacks (DoS) are a common way for hackers to take down websites, but they can also be used in more subtle ways to gain access to networks or steal information.

Statistics revealed that in 2020, the number of attacks will increase by 60% and it is likely to be a result of an increasing number of hackers and an increasingly connected cyber environment.

In this article, we’ll look at what is DoS, how they work, and how you can protect yourself against them.

What is a DoS Attack

A denial of service attack (DoS attack) is a type of cyberattack where the attacker tries to make a machine or network unavailable to its intended users. There are a number of ways to launch a DoS attack, but one common way is to flood the target with traffic from multiple sources so that it can’t handle all the requests and becomes unavailable.

In a typical DoS, the attacker will send a large number of requests to the target machine or network. This can be done by flooding the target with traffic from multiple sources, or by using tools that generate massive amounts of traffic automatically. The goal is to overwhelm the target so that it can’t handle all the requests and becomes unavailable.

(DDoS) Depth Analysis Of Working

In a distributed denial-of-service attack (DDoS), the attacker uses a botnet – a network of computers that have been infected with malicious software – to send the requests. These computers are often called zombies, and they can remain infected without their owner’s knowledge.

The volume of traffic sent to the target during a DoS attack is usually much greater than the amount of traffic the target would normally receive. The target might be a specific computer, such as a server that hosts a website or an email server, or it could be an entire network.

A DoS attack can also be used to mask another attack. The volume of traffic sent during a DoS attack is so high that it might be hard for the target to determine if there’s also an intrusion taking place, or if the traffic is just part of the attack.

DoS attacks are usually not meant to destroy data. Instead, they’re often used to gain unauthorized access to a network or computer.

How To Prevent Such Attacks?

There are a number of ways to protect yourself against DoS attacks. The most effective way is to use a firewall to block traffic from unauthorized sources. You can also use intrusion detection systems (IDS) to detect and prevent attacks.

You can also take steps to reduce the amount of traffic your target machine or network receives. For example, you can use caching to store popular content locally so that it doesn’t have to be requested from the server every time. You can also use load balancing to distribute the load across multiple servers.

In addition, you can monitor your environment to detect changes. For example, if an employee starts receiving a large number of spam messages, that might indicate that the employee’s machine has been compromised and is being used to send spam. Or if you’re expecting a small amount of traffic at certain times of day, but you notice that it’s much larger than usual, that might indicate an attempted attack.

Types of DoS Attacks

There are a number of different types of DoS. Some of the most common types include:

  • Flooding: This is the most common type of DoS attack. The attacker sends a large number of requests to the target machine or network, which overwhelms it and causes it to become unavailable.
  • Ping of death: This attack exploits a vulnerability in the TCP/IP protocol that allows a malicious user to send very large packets to a target machine. These packets can crash the target machine or cause it to become unavailable.
  • SYN flood: This attack takes advantage of a vulnerability in the way TCP connections are established. The attacker sends a series of SYN packets to the target machine, which ties up resources as the target tries to respond to them all.
  • Smurf: This attack uses a type of flood that sends requests from zombie computers to a network’s broadcast address. The goal is for the zombies to respond and effectively amplify the attack.
  • Land: This type of attack overwhelms a target server with SYN packets sent from every zombie computer on a botnet.
  • Fraggle: This type of denial of service attack sends messages from the zombie computers to the broadcast address for a UDP service. It’s similar to a smurf attack but uses UDP rather than TCP.
  • Ping flood: This type of DoS attack sends a ping from each zombie system to the targeted server.
  • Teardrop: This type of DoS attack exploits a vulnerability in older versions of Windows that allows an attacker to send malformed packets.
  • Zero-day: This attack uses malware that exploits a vulnerability that’s not yet been patched.
  • Evil twin: A wireless access point pretends to be a known network and tricks users into connecting to it. It then exploits vulnerabilities in the connection to take control of the victim’s machine.
  • Domain name kiting: This attack overloads DNS servers by creating a large number of requests for nonexistent names.
  • Email bombing: This type of attack uses automated programs to send a large number of emails, overwhelming the target’s system and causing it to become unavailable.
  • Phlashing: This attack damages a machine or network device so that it no longer works properly.
  • Distributed denial of service (DDoS): This attack uses multiple systems, all under the control of the attacker to flood the target with requests.
  • Smurfing: This attack is similar to spam bombing except it uses large groups of zombies, rather than just one.

These are the most common DDoS attacks that you’ll encounter. The main thing to remember is that the goal of a DoS is to disrupt normal operations, either by disabling services or by overwhelming a machine or system.

Final Words

hope you now have a better understanding of what denial of service attacks are and how to protect yourself against them. If you have any questions, please post a comment below.

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Rebecca James is an IT consultant with forward thinking approach toward developing IT infrastructures of SMEs. She writes to engage with individuals and raise awareness of digital security, privacy, and better IT infrastructure.

1 thought on “Denial-of-service attacks (DoS) – Types And Preventions A Complete Guide”

  1. Thanks for raising awareness on the scourge of DDoS attacks. As you noted, they are becoming more and more frequent. Incapsula, a DDoS-mitigation provider, just came out with new research that showed that attacks are growing shorter, more complex, and persistent – making DDoS mitigation all the more important.

    I don’t want to make a sales pitch but at the moment an attack is taking place, it’s going to be very hard to stop it. Your web server might not have the capacity (depending if it’s a small attack from a neighbor kid using a booter or a large attack like we saw on Dyn or using Mirai botnet). You should plan in advance, see if you or your ISP have a mitigation provider with always-on or automatic detection, or a 24/7 NOC.As the boy scouts say, the best way to deal with a DDoS attack is to prepare for one before it happens.


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